Railway train operating and dispatching system



July 19, 1938. A. G. SHAVER 2,124,452

RAILWAY TRAIN OPERATING AND DISPATCHING, SYSTEM Original Filed May 30, 1931 2 Sheets-Sheet 1 A. G. SHAVER July 19, 1938.

RAILWAY TRAIN OPERATING AND DISPATCHING SYSTEM Original Filed May 30, 1931 2 Sheets-Sheet 2 A TORNEY STATES PTENT OFFICE RAHJWAY TRAIN OPERATING DIS- PATCHING SYSTEM Archibald G. Shaver, Chicago, 111.

Application May 30, 1931, Serial No. 541,131

, Renewed July 13, 193? This invention relates to railway train opare modified in such manner that the means crating and dispatching systems and has special used for communication between rear end and reference to the provision of improved means head end of trains do not normally include the for communication on and with trains and the transformer employed for communication beoperation of track switches and signals for trains tween the train and the dispatcher. In this in- 5 to enter passing sidings to meet and pass other venti'on, devices are provided for connecting the trains. transformer into the intermediate circuit and More specifically, the present invention is rethe dispatcher's communication circuit when lated to the type of train operating systems decommunication between the dispatcher and the scribed in my applications for letters Patent train isdesired. With this arrangement better 10 filed October 22, 1927 under Serial No. 227,932, results are attained for rear end to head end September 7, 1928, under SerialNo. 304,483, communication in that the impedance of the and July 13, 1929' under Serial No. 378,000. In intermediate circuits is lowered, andlonger interthese pending applications, the systems of train mediate circuits, with consequently longer comoperation disclosed provide means for communimunicating zones, are possible where desired; 15 cation between the conductor on the rear and Another object of the invention is the provithe engineman on the head of trains and between sion of means whereby one device serves to con-1 the train dispatcher and either the conductor or nect two intermediate circuits with the disthe engineman, or both, that information may patchers circuit instead of one device for each be had by each and instructions issued with reintermediate circuit for such connection, as is 20 gard to the operation of trains, including trains the case in the disclosure of the pending applioperating into and out of passing 'sidings in cations referred to. meeting and passing other trains. Further, in Another object of the invention is the provi-, connection with the means for communication sion of separate train carried inductors for transthere are means for the operation of the switches mittin'g and receiving communications on the 5 and signals concerned for trains to enter and train. leave sidings and pass other trains. In these Provision is made for train operation in a systems each train operates in a communication stretch of track containing alternate sections of zone of its own which always includes at. intersin le a d double track Where the track Switch :0 mediate wayside circuit. The stretch of track is always set to enter the double track secover which the trains operate is sectionalized and tions, and trains leaving double tracl;v may trail an intermediate circuit is provided for each sec through the switch w h Stoppingtion; but as, and during the interval. the train Still another obj of the invention is an travels from one section to the next, the two rangement for control of the switch, signal and intermediate circuits for the adjoining sections communication circuits by the dispatcher and 35 are automatically connected together, thus crethe control by the dispatcher of the stopping ating a traveling circuit efiect. Each intermeand st ti f the power p a s which furnish diate circuit is so arranged as to be in continuenergy for th operation of e sw t s, si nals ous communicative relation with both ends of and communication control at passing siding lothe train as the train travels through the cor- Cations- 40 responding section. and each such circuit is also i To the accomplishment of the foregoing and provided with'means for communicative con- Such other O j as may hereinafter ppear. nection with the communicationmea provided my invention consists in the elements and their for the dispatcher. relation one to the other, as hereinafter pari For entering and leaving passing siding means ticularly described and sought to be defined in 45 are provided, that the track switch may be opthe claims, reference being had to the accomerated either from the approaching train or by panying drawings which show a preferred emthe dispatcher, and the signals are controlled to bodiment of my invention, and in which:- protect and authorize the movement of the train Fig. 1 is a diagrammatic view of a portion of over the switch. all in accordance with the una stretch of single and double tracklshowing the 50 derstanding had between the conductor, enginecommunicating system. 1 man and train dispatcher. Fig. 2 is a diagrammatic view of the arrange- For the system which is the subject matter ment and control of signals at-the ends of a of the present invention, the systems disclosed section of double track.

in my pending applications. referred to above, Fig. 3 is a diagrammatic view of the inductors. 55

circuits and communication apparatus carried on the train.

Fig. 4 is a diagrammatic view of the communication system circuits including means for the 5 dispatcher to connect his circuit with a train.

' Fig. 5 illustrates means for selectively operating circuit contacts.

Fig. 6 is a diagrammatic view of circuits and means for operating a track switch including a 10 power plant for furnishing electrical energy.

Figures 1, 2, 4 and 6 are fragmentary showings of a stretch of railway track in which TI and T2 are the track rails, BX is a battery for a track circuit, the insulated joints are represented by a short straight line across the line representing the track rails and are generally designated by J, the track switches are designated F followed by Y -a sufilx, the manually operated track switch stands are designated by G followed by a number which is thesame as that used for the corresponding track switch, track circuit relays are designated E followed by a suffix, signal control relays are designated by C followed by a number for each which is the same as that of the signal to which it refers, selectors are designated by L followed by a sufifix, relays co-operating with selectors are designated by K each followed by a number which is the same as that for the selector with which it is associated, and the transformers so are designated T followed by a-suflix to agree with that for the corresponding selector. The symbols used in the drawings for the signals, relays, relay contacts, batteries, circuits, etc., are those conventionally employed. In these figures 35 various features of the invention are shown segregated to more clearly illustrate the invention.

Fig. 1 illustrates a portion of railroad representative of a district in which there are alternate sections of single and double track. The general 40 arrangement of the communicating system is illustrated in this figure.

CS is generally representative of a section of double track with the switches F2 and F3 normally-set for trains to enter the double track.

45 BS is generally representative of a section of single track located between .two sections of double track. The section AS is a partial view of another section of double track in arrangement like CS. The section DS is a partial view of an- 50 other section of single track in arrangement like BS. GI G2 and G3 are switch stands for manually operating the track switches Fl, F2 and F3 respectively. In the connection of each of these switch stands to the track switch is a device as 55 HI, which permits trains to leave sections of the double track without it being necessary for an attendant to set the switch for such movement. In such train operation the train trails through the track switch without causing damage. Sig- 60 nals I to 12 are block signals with the added function of controlling the passage of trains to and from the sections of double track. The circuits for these signals governing traflic to, from and i ductor I8 or 20 is always so locatedon the railover the double track section, are illustrated in 65 Figure 2. The circuits for the signals governing trafllc on the single track sections may be in ac-- :iordance with any of the various known pracces.

The railroad is divided into sections for track 70 circuit purposes, arranged in accordance with the usual track circuit practice. In Figure 1 the track relays are shown controlling only the contacts operated in connection with the communication system. 75 D1, DR and DSE are respectively, transmitter,

receiver and selective equipment in the train dispatchers oflice. W is a switch arranged for operation by the dispatcher to connect the conductor H3 with either DSE, DR or DT as required. Normally, this switch is in connection 5 with DR, and preferably is so biased by a spring or other suitable means. DI and D2 are wayside conductors along the railroad connected with the dispatchers telephone and selective equipment, and constitute what is generally re- 10 ferred to as the dispatchers telephone line". Li, L2, L3, etc., are selectors adapted to be operated by the dispatcher in connection with his selective equipment DSE to control relays Kl, K2,

K3, etc. These relays K close circuits in either 15 of two positions. Such relays are generally known as off and on relays and the actual contact operating members may take the form of the cam and ratchet arrangement shown in Figs. 5 and 6. The selectors Ll, L2, and L3 respec- 20 tively control contacts 42, 46 and 50. With any one of these contacts closed, the corresponding relay K is energized to shift its contacts, which remain in the position to whichshifted until the selector is again energized to close its contact when the relay K shifts its contacts to the other illustrated position. H is a relay controlled by contacts of the track circuit relays E5, E6, E1 and E8. The function of this relay under normal conditions is to connect the intermediate circuit for the double track section CS to the dispatchers telephone line Di and D2 for communication with the dispatcher so that the train attendants may initiate the conversation.

The intermediate circuits for sections BS and CS are typical of the single and double track section arrangement. There is only a partial showing of the intermediate circuits for sections AS and DS. The intermediate circuit for section I AS when shown complete would be like that illus- 40 trated for section CS and the intermediate circuit for section DS if shown complete would be like that illustrated for section BS.

Shown within the section BS is a train No. 6 with a rear end car or caboose CA and a 1000- motive L0 at the head end. Shown on track M2 of the double track section CS is a train No. 5 also with a car or caboose CA at the rear end and a locomotive LO at the head end. These two trains illustrate a condition where train No. 6 will proceed along the single track main line into track Ml of the double track section passing train No. 5 while the latter is on the track M2. As the trains leave the section they will pass over the switches, as F2 and F3, without stopping, as heretofore explained.

Z illustrates a sub-section of any arbitrary length. I

The intermediate circuit for section BS normally comprises conductor l8, contact 19, conductor 20, contact 2| and back contact 22. The conductors l8 and 20 are transposed at intervals to form an equal number of loops. Either conroad, preferably in the center of,the track on the ties, as to be in inductive relationship with the inductors carried on the train.

The intermediate circuit for double track section CS normally comprises conductor 23, contact 24, conductor 25, contact 26, conductors 21 and 30, and contact 29 closed. It will be noted that as illustrated there is a conductor for each track. While but one transposition is shown, others, to make an equal number of loops, may be provided if necessary. Since train No. 5 shunts arsensa the circuit for relay E0, this latter is de-energized, opening its front contactASfl, which results in relay H being de-energized to open its front contact 29 and close its back contact 38. The intermediate circuit for-section CS is now closed through front contact 28 and coil S of transformer T3. Also, primary P of transformer T3 is connected to the dispatchers telephone line conductors DI and D2 by conductor 4|, contact 40, conductor 39, back contact 38 closed, transformer primary P and conductor 31.

The selector L! is connected across the conductors DI and D2 by the conductors 6! and 33.

Selector L2 is connected across the conductors DI and D2 by the conductors 08 and 36. The selector L3 is connected to the conductors DI and D2 by the conductors 31 and 4|.

The circuit for relay ,KI comprises battery BI, conductor 43, contact 42 normally open, conductor 45, coil of relay KI and conductor Ml. The circuit for relay K2 comprises battery B2, conductor 51, contact 46 normally open, conductor 69, coil of relay K2 and conductor 58. The circuit for relay K3 normally comprises battery B3, conduc-.

tor 53, contact 50 normally open, conductor 5i, coil of relay K3 and conductor 52.

That much of the partial intermediate circuit for section AS, as is shown, comprises conductor I'I, back contact I6, conductor I5, contact It and conductor I3.

That much which is shown of the partial intermediate circuit for section DS comprises conductor 63, contact 64 and conductor 65.

The circuit for relay H comprises battery BY, contact 55, conductor 56, contacts 57 and 58, conductor 59, coil of relay H, conductor 50, contact A60 normally closed, and conductors M and 62. It will be noted by reference to Figure 6 that battery SY and generator UI are illustrated as a source of energy for relay H and its circuit, as an alternative for battery BY.

Conductors Iii and H3 connect DT, DR and DSE to conductors Di and D2, depending upon the position of switch W.

Figure 2 is typical ofthe signal arrangement for a section of double track as CS. Trains move right-handedly on the tracks. Signals Sand e govern trains entering the double track in accordance with the established direction of trafilc. Signals 8 and II govern traffic over the track switches F2 and F3 into the double track in the direction against the regular current of tramc. Signals 5 and I0 govern train movements from double track to single track, in accordance with the established direction of traflic. Signals I and I2 govern trains from double track to single track against the established current of traffic.

Contacts 12 and it 'are connected for operation when switch F2 is opened and closed, contact 59 being closed with switch F2 in the normal or closed position and I2 being closed with switch F2 in the open or reverse position. Contacts 9'? and E04 are connected for operation when switch F3 is opened and closed, contact @i being closed with switch F3 in the normal or closed position and contact I 0 3 being closed with switch F3 in the open or reverse position.

Relays C5 to CIZ inclusive are the relays for controlling the correspondingly numbered signals; that is,- control relay C5 operates to control signal 5, etc. CMI and CM2 are commutator devices or contacts selectively controlled by the dispatcher, in some such manner as illustrated in Figure 5 and as hereinafter referred to. The shaded section of each of these commutator conmutator or contact in its respective circuit, for example. contacts OI and 03 are normally in the position closing their respective circuits. Contact 02 closes its circuit only when operated to its fourth position. Contact 03 also closes its circuit in position three. Contact 04 closes its circuit in position three. The circuits connected with the commutator devices CM! are generally closed as explained for commutator device CM! 'and as recited in Figure 2.

The circuit for control relay C6 comprises common conductor C, coil of relay C6, conductor I6, relay contact "i'l, switch operated contact '19 closed, conductor 80, normally closed contact of commutator 03, conductor 8i, contact 82 closed, conductor Ill and through the other circuit controlling contacts of the block, if any, to battery and common conductor C. The circuit for control relay Cl comprises common conductor C, coil of relay Cl, conductor 87, contact 02 normally open and conductor 88 to conductor 84, and then proceeds in common with the circuit for control relay C5 already explained. The circuit for control relay C0 comprises common conductor C, coil of relay C$,'conductor 39, contact 10, conductor it, normally open switch controlled contact #2, conductor it, normally open contact Oil, conductor id, contact 15, conductor H8 and through other circuit controlling contacts of the block, if any, to battery and common conductor C. The circuit for control relay C9 comprises common conductor C, coil of relay C9, conductor 95, normally closed switch controlled contact. 97, conductor 98, contact 99, conductor I00, normally closed contact 07, conductor Iill, contact I02, conductor 5 l6 and through other circuit controlling contacts of the block, if any, to battery and commonconductor C. The circuit for control relay CHO comprises common conductor C, coil of relay Cill, conductor Bil, normally closed commutator contact 06, conductors 90 and 92, relay contacts 93 and Q6, conductor 95 and through other circuit controlling contacts of the block, if any, to battery and common conductor 0. The circuit for control relay CII comprises common conductor C, coil of relay CI 5, conductor I03, normally open track switch controlled contact I04, conductor. I05, contact 808, conductor I01, normally open contact 08, conductor I08, contact I09, conductor I I0 and through other circuit controlling contacts of the block, if any, to battery and common conductor C. The circuit for relay C!2 comprises common conductor C, coil of relay C I 2, contact 05 normally open, conductor 92 and thence common with the circuit for control relay om, already explained, to battery and common conductor C.

The signals illustrated in the various figures, including those in Figure 2, may be of eitherthe two or three position types and they may be semaphores or' light signals. For convenience, the semaphore type is illustrated. The corresponding control relays, as C5 'to CI2, may be of the ordinary electro-magnet type for two position signaling or of the polarized type for three position signaling. Two position and three position signaling is well known in the art as are also tacts illustrates the closed position of the compolarized relays. I have not illustrated means 75 for controlling the circuits for three position signaling since that is not especially pertinent to the.

invention.

Figure 3 is a diagrammatic illustration of the circuits and equipment for locomotives and cabooses. Two inductors RN and TN, each comprising a coil on an iron core, respectively for receiver RE and transmitter TR, are mounted on locomotives and cabooses so as to be in inductive relationship with the intermediate circuits heretofore explained. The circuit for transmitter TR comprises conductor I55, normally open circuit controlling contact I68, conductor I58, coil I51 of the inductor TN, and conductor I56. The circuit for the receiver RE comprises conductor I5I,

' normally closed circuit controlling contact I59,

conductor I54, coil I53 of inductor RN and conductor I52. The switch SH is arranged to control both the transmitter and receiver circuit, such that only one can be closed at a time. Under certain conditions I may dispense with the use of this switch, in which case the inductors RN and TN are so mounted and the circuits so protected that there may be simultaneous transmission and reception of communication signals without the necessity for opening the circuit for receiving when it is desired to transmit. With such an arrangement, transmission and reception of communicating signals, voice communication forinstance, may be carried on in a manner similar to that for the usual public telephone systems. 28 illustrates a preferred position of a conductor of the intermediate circuit with reference to inductors RN and TN, as, for example, conductor 23 of intermediate circuit CS which has. a similar relationship with the inductors on the locomotive L0 and caboose CA of train No. 5.

The transmitter TR and the receiver RE are assumed to be suitably arranged for either audio or radio transmission of communication signals, depending upon which system is used. In general, it is desirable to so design these units that,

the transmitter output will be relatively large and the receiver amplification, where required, will be relatively small. This is particularly true where communication is carried on with audio frequency, and there is probability of foreign inductive disturbances affecting the reception. In the use of radio frequencies in this communicating system,

I may alternatively, employ the loop type of inductors rather than those with iron cores as illustrated. Figure 4 is illustrative of the wayside'communicating system applied to a stretch of track with special reference to means for connecting the dispatchers selective and telephone circuit, conductors DI and D2, with two intermediate circuits at the same time. In the case of a double track railroad, the arrangement as disclosed would either be duplicated, or, instead of having conductors on each of the tracks interconnected, the track conductors would be connected with separate conductors on a pole line. The intermediate circuits may each be completely on the two tracks, with one conductor on one track and another conductor .on the other track, the two connected together at the ends of the section making a complete loop. In the case of this latter arrangement, track circuit sections in the second track, not shown herewith, would control the respective track 'relays EIII, EI I, EI2, etc., of the track shown such that,

as the train passes over the second track, the various intermediate circuits would be operated shown.

In the figure are two complete intermediate circuits, one for section FS and the other for section- GS. Only partial intermediate circuits are shown for the partial sections ES and HS; but if these contact I25, conductor I21 and front contact I28.

For the section GS the intermediate circuit comprises conductor I29, front contact I30, conductor I3I, back contact I32, conductor I33 and front contact I 54.

With relay EII de-energized the contacts I34, I25 and I38 are made on their back points so that the intermediate circuits for sections FS and GS are connected together into one enlarged intermediate circuit comprising conductor I23, back contact I24, conductor I25, back contact I26, conductor I29, front contact I30, conductor I3I, back contact I32, conductor I33. back contact I34, conductor I21 and front contact I28 connecting to conductor I23.

It will be noted that normally each illustrated section has two equal loops because of one. transposition in each section. With the relay EII deenergized another transposition is effected, making in the enlarged intermediate circuit, four equal loops. v

The circuit for relay K4 comprises contact I48,

conductor I49, battery B4, conductor I46, coil of relay K4, and conductor I 41. With contact I48 closed, which may be but momentarily, relay K4 is energized, shifting its contacts I24, I32 and fore, be noted that with the train in the section of relay EI I; not only are the two intermediate circuits for sections FS and GS joined together as one circuit, but with the dispatcher having operated his selector L4 to place his communieating set in communication with they train, but one secondary coil S2 remains connected in the enlarged intermediate circuit so long as it remains as such. With relay EII normal, the separate intermediate circuits for section FS and GS are again effective. When the dispatcher again operates selector L4, the relay K4 shifts its contacts back to normal and the transformer secondaries SI and S2 and primary P again resume normal status.

The functions of the relays EIII and EI2 are 'simply that of connecting the adjacent intermediate circuits, that is, ES and FS, together while the-train is in the circuit of Eli! and GS and HS together while the train is in the circuit of EI2. Assuming relays EIIl, EI I and EI2 each to represent a track circuit location, the arrangement as shown at the location for EII, is repeated for every other track circuit location. In this way the dispatcher by operating one selector, like L4, placed at every other location, is enabled to connect his selective and telephone circuit, conductors Di and-D2, with every intermediate circuit for the track stretch.

In Figure 5 is shown a method for operating a plurality of commutator contacts from one selector; for example, the commutator combinations CMA and (EMS. L5 is a selector operated from the dispatchers ofllce over conductors DI and D2 by the selective equipment DSE. Whenso operated,

contact 232 is closed, which may be but momentarily. 236 is a gear or toothed wheel. When contact 232 is closed, relay K5 is energized from battery B5 through conductor 234, coil K5, conductor 233, contact 232 and conductor 23E. This causes armature 235 to be raised, such that the latch connected with it causes gear 236 to rotate counter-clockwise each time K5 is energized. Commutators O9, om, and CI hare on the same shaft and movable with gear 238. The circuits connected with these commutator contacts are made and broken as desired. As illustrated in Fig. 5, four positions are obtainable. While I have shown this particular detailed arrangement for operating commutator contacts, there are other equally efllcient methods of accomplishing the same purpose. Therefore, I do not want to be confined to the use of the particular arrangement shown.

In Figure 6 is illustrated means for the dispatcher to operate the track switch F2, and to control the power plant for furnishing the energy for operating the switch F2 and for operating the signals which govern trafllc 'over the switch F2. HTS is a hand throw stand for manually operating the'track switch F2. SM is a mechanism for operating the switch F2, and M is the motor which drives the mechanism. v

6 is a signal governing trains over the switch along the main line. 8 is a signal governing trains. from the main line into the siding. 5 is a signal adapted to govern trains from the siding to the main line. 1 is a signal arranged to govern trains along the main line trailing over the switch.

The control relays C5 to C8 control respectively signals 5 to 8. The circuit for relay C6 comprises common conductor CW, conductor ISI, front contact I52, conductor I53, coil of relay C8, conductor I58, normally closed commutator contact om, contact I59 closed when switch F2 is in normal position, contact I60 closed when switch F2 is locked, and thence through other controlling contacts of the block, if any, to battery and common conductor CW. The circuit for control relay C2 comprises common conductor CW, conductor I5I, contact I52, conductor I53, coil of relay C8, conductor Q54, contact I55, closed only when switch F2 is open, contact I58 closed when switch F2 is locked in the reverse position, conductors I57 and 224, battery SY to common conductor CW. The circuit for relay C5 comprises common conductor CW, conductor I12, coil of relay C5, conductor I89, contact ISI closed when switch F2 is locked in the 7 reverse position, contact I92 closed only when switch F2 is open, conductor I92, contact I92, contact I94 and conductor l95 through other circuit controlling contacts in the block, if any, to battery and to common conductor CW. The circuit relay location comprises gasoline engine GE directly connected to generators UI and U2. ST is the starting motor, which, when energized, connects itself through a clutch with engine GE to start same operating. Battery SY furnishes energy for the starting motor ST and for the various relay and signal circuits. S is a circuit controller fastened to the common shaft of the gasoline engine GE and the generators UI and U2. The contact 225. is normally closed, but opens when the speed of the gasoline engine GE reaches a point where it is self-operati Thus, when this point is reached, the starting motor ST is tie-energized and disconnected from gasoline engine GE. The generator UI furnishes energy for charging the battery SY and for operating the various relays and signals as indicated and explained. HR is an electrolytic cell, or other device, to prevent a reversal of current; that is, a flow of current from battery SY to generator H6, in case, for some reason, the voltage of the current delivered from UI falls below that for the battery SY. 0M2 and CM are assemblages of commutator contacts each operated selectively by the dispatcher. SR is a relay for controlling th operation of the motor M.

When contact 225 is closed, signal 5 becomes operative to authorize an. approaching train to proceed over the switch along the main line. Its circuit comprises common conductor CW, conductor 222, mechanism of signal 6, contact 265, conductors 2M and 226, and battery SY connected to common conductor CW. When con tact 2% becomes closed by reason of relay CB being energized, the circuit just described is closed between conductors 2M and 222 and signal 2 becomes operative to authorize a train to proceed into the siding. When relay Cl is energized, closing contact 201, signal 7 becomes operative to authorize a train to proceed over the switch along the main line, energy being furnished through contact 287 from conductors 2B! and 202- when contact 226 is closed, signal 5 becomes operative for a train to move from siding to main line due to the circuit being closed between battery leads, conductors 2M and 202.

The circuit for the starting motor ST comprises common conductor CW, battery SY, conductor 224, motor ST, conductor 225, contact 226, conductor 221., commutator contact OI3 closed in position 2, and conductor 228, connected to common conductor CW.

@P is a battery or magneto in the ignition circuit for the gasoline engine GE. This ignition circuit comprises battery BP, conductor 2I5,

"ignition contacts in. engine GE, conductors 2I6 and 2 I1, commutator contact OI2, closed in position 2, and ignition energy .BP. The circuit for relay SR comprises common conductor CW, conductor- 223, commutator contact OII closed in position 3, conductor 222, coil of relay SR, conductor 22I and battery SY connected to common conductor CW. The circuit for motor M to open the switch F2 comprises generator U2, conductor 2| 4, contact 2I3, conductor 2| 2, contact 2| I closed on its front point, conductor 2I0, motor M and conductor 208 connecting to generator U2.

For closing the switch F2, the circuit is as above described, excepting contact 2 is closed on its back point, and conductor 209 connecting to 1 motor M completes the circuit.

Contained in the mechanism for motor M is a. circuit controlling device so arrangedthat when the motor is operated to open the switch, the

operation of locking the switch in the open posi- 7'5 tion opens the circuit normally closed over conductor 2H! and closes a circuit over conductor 209. When the switch has been operated to the closed position and is being locked, the circuit controlling device, above referred to, again operates, opening the circuit closed over conductor 20!) and reclosi'ng the circuit over conductor MD. This is a well known practice in electric power switch operation incorporated in the systems of various signal companies.

Also getting energy from battery SY and generator Ui, through the conductor 237, contact 238 and conductors 2M and 224, and returning through common conductor CW, is the control relay (not shown) for the distant signal (also not shown) for signal 6. The relay H of Fig. 1 is also shown by the partial circuit, contacts 58 and 51, conductor 56, contact 55, conductors 20! and 224, battery SY and common conductor CW as getting its energy from the power plant of Fig. .6 in the case that the track switch F2 of Fig. l is power operated.- The conductor CW under such circumstances compares with the conductor 52 of Fig. 1.

The hand throw switch HTS has two levers. In operation, one lever disconnects the power mechanism SM and the other then operates the switch F2.-

Operation Referring to Figure 1, assume trains No. 6 and No. 5 have to pass each other. Dispatcher instructs train No. 5 as it approaches station Y that train No. 6 will-pass it while it is in the double track section CS. He also instructs train No. 6 as it approaches station Y that train No. 5'

will be passed in the section CS. As a precaution that neither train will leave the double track section till both trains have arrived within the section, the dispatcher causes signals 5 and Ill to indicate stop. After having received the dispatchers instructions, the conductor in the caboose and the engineman in the locomotive cab of each train confer with regard to the dispatchers instructions, and arrangement between themselves is made as to such details for operation of their respective trains as are necessary.

Upon the arrival of each train within the section CS, each conductor will report the arrival of his train to the dispatcher. communication with the engineman to make certain of the identity of the other train as it is passed. The dispatcher will then release each of the signals 5 and In that each train may proceed. If the two trains have arrived in the section CS before either has stopped for its respective outbound signal (signal 5 for train No. 5 and signal ill for train No. 6), the dispatcher will release the signals to clear so that each train may proceed without having to stop. As each train leaves the double track section CS, for example when the train No. 5 is in the track circuit of relay E5 and train No. 6 is in the track circuit for relay E8, the conductor of the train advises the dispatcher of that fact, the location of the train, and any other information desirable for the dispatcher to have in connection with the proper operation of trains.

As heretofore stated, Fig. 2 is typically illustrative of the normal arrangement of signals, circuits and operative devices for'signals for the double track sections in the stretch of track referred to in Fig. 1, and for this purpose is arranged as applying to the section CS.

In Fig. 1, signal 5 is at stop because oftrain He will also engage in No. 6 within its block and signal i0 is at stop double track section CS before train No. 6 had entered the block of signal 5.

Considering now the procedure in the passing of the two trains No. 5 and No. 6 as referred to above, the dispatcher communicates with train No. 5 and gives it the instructions while it is within the section D8, which is but partly shown.

It has been heretofore stated that the communication arrangement for section DS is similar to that for section BS, and therefore, the procedure in instructing train No. 5 and receiving a reply may be considered the same as that which follows for train No. 6.

In communicating with train No. 6 in the section BS, the dispatcher first operates switch W and causes the selective equipment DSE to operate to send out the code of current impulses to which selector L2 is responsive, these impulses following the circuit of conductors H3, iii, Di, D2, 68 and 36. When selector L2 responds contact 46 closes causing relay K2 to close its contacts 22 and 35 on their front points. This operation connects primary P of transformer T2 to conductors Di and D2 at contact 35 and secondary .S into the intermediate circuit for section BS at contact 22. The dispatcher next closes switch W on conductor H2 to connect the transmitter DT to conductors DI and D2. He now transmits his communication signals (assume they are voice signals) in the form of electric impulses to the circuit including the conductors Di and D2 and coil P. These signal impulses are induced from coil P into the intermediate circuit for section BS, through the secondary S of transformer T2 and conductors i0 and 20. Since the receiving sets RC and RL of the caboose 'and'locomotive respectively, each of which includes the inductor RN in circuit with receiver RE, are normally in inductive relation with conductors 20 and I8, the

signal impulses are picked up by the respective where they are transformed into the communieating signals which the dispatcher transmitted. As soon as the transmission of the instructions is complete, the dispatcher closes switch W (usually it will be arranged to automatically sooperate) to the form of communicating current impulses pass through the coil ii! of the inductor TN, thus setting up a magnetic field which induces corresponding current impulses into the intermediate circuit including conductors i8 and 20 and secondary S' of transformer T2. Within transformer T2 these signal impulses are induced into the primary 1?, including the conductors DI and D2 inductors RN and carried to the receivers RE I and the receiver DR where they are transformed into the communicating signals (speech) transmitted by the conductorand engineman of train No. 6. When the conversation is finished, the dispatcher again operates switch W to close the circuit for the selective equipment DSE to send a code of impulses to selector L2 which responds, closing contact 46. Thus relay K2 is energized to again shift its contacts to the normal position, that is, closing contact 22 on its back point and opening contact 35. This operation'disconnects the dispatchers circuit from intermediate circuit of section BS.

Should the dispatcher have found it more convenient to do so, he might have operated the selector L2 for the section BS and the appropriate selector (not shown) for the section DS connecting the respective transformers in the circuit containing conductors Di and D2, so that the intermediate circuits for sections BS and DS would be connected to the conductors Di and D2 at. the same time. Then he could have simultaneously given his instructions to trains No. 5 and No. 6. The replies from each train, acknowledging the instructions, could then come in one following the other in the order in which he would indicate.

The dispatcher now causes the signals 5 and ill to indicate stop. In Fig. 5 it was indicated how commutators such as CMI and CMZ are operated. The dispatcher, first sends out a series of the appropriate code of impulses to cause the selector for GM? to operate the latter to position 3, closing contact and opening contact 08, which places the circuits in condition for signal 9 to indicate proceed and signal it to indicate stop. He again sends out a series of appropriate impulses to operate the selector corresponding to commutator CMi, operating this commutator to the position 3, to place the circuits through contacts OI and 03 for signals 5 and 5 in condition for signal 5 to indicate stop and signal 8 to indicate proceed. Following communication from and with the dispatcher, the conductor and engineman of each train communicate with each other with reference to the instructions from the dispatcher and other matters pertaining to the operation of the train in passing other trains, including identification of the trains passed.

The train No 5 being assumed still in the section DS, the procedure in the communication between the conductor and englneman will be similar to that which is now about to be described for train No. 6. The conductor of train No.33 initiates the conversation byoperating switch SH of his set RC-TC to open the receiver circuit and close the transmitting circuit. He then transmitscommunication current impulses which energize the inductor TN to induce corresponding impulses into the intermediate circuit which includes conductor 20. As this intermediate circuit is closed, including also conductor it which is transposed with conductor 20, the electrical impulses corresponding to the communication signals are carried through this closed circuit as heretofore described. The receiving set RL on the locomotive being in communicative relationship with conductor 20, the inductor RN-is infiu-' enced to transmit the corresponding communicating current impulses to the receiver RE where they are transformed into the communicating signals transmitted. These signals may be either by code or by voice. The conductor's switch SH is now restored tonormal condition. The engineman, in replying. to .the conductor, operates 'tors Di and D2.

switch SH of his transmitting and receiving sets TL and RL respectively, opening the circuit of the receiver RE and closing the circuit of the transmitter 'I'R. He then transmits communicating impulses into the inductor TN on the comotive. This influences the intermediate circuit, of which conductors i8 and are a part, so that electric impulses corresponding to the transmitted signals pass through this intermecase the intermediate circuits for sections BS and CS are combined and the communicating impulses between the head end and rear end will then pass through this enlarged intermediate circuit, which has been heretofore described.

Normally, the relay K3 is in the position shown. With train No. 5 operating on track M2 of section CS in the position shown, relay E8 is deenergized, opening the circuit of relay H. With front contact 29 open, the intermediate circuit for the section CS is connected through the secondary S of transformer T3. With the back contact 38 closed, the primary P of transformer T3 is connected across the dispatchers line, conduc- The conductor of train No. 5 may now talk to the dispatcher. He operates switch SH of his receiving and transmitting set ESP-N, opening the circuit for the receiver RE and closing the circuit for the transmitter TR. He transmits the communicating impulses announcing his arrival on track M2 into the circult of inductor TN, energizing same with electrical impulses corresponding to the communicating impulses transmitted. These electrical impulses influence the conductor 23 of the in-- termediate circuit for section CS, thus causing these impulses to pass through the secondary S of transformer T3 where they are induced as corresponding current impulses in the primary P of the transformer T3 and through conductors Di and D2 to the dispatchers receiver DR, which is normally connected with the conductors DI and D2. In the dispatchers receiver DR these current impulses are transformed into the communicating impulses transmitted by the conductor from the train. If the dispatcher wishes to reply or give any information to train No. 5 he shifts his switch W to conductor H2, thus connecting his transmitter DT with the conductors Di and D2 and proceeds to transmit his reply as communicating impulses into the circuit including conductors Di 'and D2 and the primary of RC have again been placed in normal commu-- nicative relationship with the intermediate circuit, including the conductor 23, the electrical communicating impulses influence the inductors RN of these sets on both ends of the train such that corresponding impulses are carried to the receivers RE and transformed into the communicating signals transmitted by the dispatcher. when train N0. 6 arrives in the circuit for track relay E5, the latterlis tie-energized, openin'g contact 55, which would de-energize relay H" were it not already -de-energized dueto train I No. 6 in announcing the arrival of his train within the section CS and by the dispatcher in making a reply, if any, is the same as that already explained for train No. 5. 7

Should the dispatcher find the exchange of communications between conductors and engineinen bothersome, he may disconnect the intermediate circuit for section CS from the'conductor DI and D2 by operating selector L3 to cause relay K3 to shift contact 28 toits back point and open contact 40. Such operation leaves the intermediate circuit for section CS in condition for inter-train and intra-train communication.

As trains No. '5 and No. 6 are now both in the section CS and their train carried communication sets are in communicative relation with each other through the intermediate circuit for C8.

the conductors of each train, or'the engineman of each train, or all of them, may communicate with each other in exactly the same manner as heretofore explained for conductor and engine- 'man on the same train, and thus each may establish for a certainty the identity of the train being passed and exchange such other information as seems desirable.

Since the dispatcher is advised that both trains are now in the double track stretch CS, he will close the switch W on conductor H5 and operate the selective equipment DSE to send out the appropriate code to operate the selector control- W ling commutator CMI, stepping the commutator indicate proceed" providing its block is clear,

I for train No. 5 to enter the single, track stretch BS and continue on its way. Thedispatcher also sends out the appropriate code for the selector controlling commutator CMZ stepping same around to its normal position or positionl. This completes the circuit for control. relay CIII through contact 06 so that signal III may indicate proceed, providing its block is clear, so that train No. 6 may pass from the double track section CS into the single track section DS.

As train No. 5 is about to leave track M2 to enter the single track section BS, the conductor of this train operates his swtich SH opening the receiver circuit of his receiving set RC and closing the transmitting circuit of the transmitting set TC. Relay K3 having been restored to normal, he announces in the transmitter TR to the dispatcher that the train is leaving the double track section CS. This causes current impulses, corresponding to the signals transmitted, in the circuit of inductor TN on the caboose, thus influencing the intermediate circuit for section CS of which conductors 25 and 23 and transformer T3 are a part. These current impulses are induced from the secondary S into primary P and thus into the dispatchers circuit containing conductors DI and D2 and carried to the dispatchers receiver DR, where they are transformed into the transmitted communicating signals.

As train No. 6 leaves the section CS, its conductor also announces the departure. of that train into the single track section DS and the procedure in making the announcement is similar to that already described for train No. 5. I

When train No. 5 passes into the circuit for track relay E4, the intermediate circuits for sections CS and BS are combined into one enlarged intermediate circuit. 'During this. time and until the train leaves the circuit for track relay E5, communication may be initiated with the dispatcher. Similarly, this is true for train No. 6. As it enters the circuit'of track relay E9, the intermediate circuits for sections CS and DS are combined. During the time the train is in this track circuit, and until it clears the track circuit of relay E8, communication with the dispatcher may be initiated on the train No. 6. In cases where such may be desirable, the engineman, instead of the conductor, may report to the dispatcher that the train is leaving the section CS and he may initiate the conversation similarly as referred to above for the conductor.

While one of the trains referred to is in the track circuit for relay E4 and the other train is in the circuit for track relay E9, there may be communication between their train carried communication stations via the enlarged intermediate,

circuit for the sections BS, CS and DS. Relays E4 and E9 being deenergized, the intermediate circuit for the section CS is connected at one end with the intermediate circuit for section BS and at the other end with the intermediate circuit for section DS.

In Fig. 4 is shown a somewhat different arrangement for the dispatcher to connect his station with the intermediate circuits for communi-;

cation with a train. If the dispatcher wishes to have communication with a train in either section FS or GS, or trains in each of these sections, he will move his switch W (see Fig. 1) from the normal position to connect with conductor H5, and send out a code of impulses to which selector L4 will respond. When contact I48 is closed, relay K4 is energized to shift its contacts I24, I32 and IM to their front points, the latter connecting primary P to conductors DI and D2. The closing of front contact I32 connects secondary SI of transformer T4 into the intermediate circult for section GS. The closing of front contact I24- connects secondary S2 into the intermediate circuit for section FS. The dispatcher may then initiate and carry on communication with trains in either or both of these sections similarly as heretoforeexplained. Should he be communicating with the train in section FS and it should proceed into the circuit for track relay EI I, then the intermediate circuits for sections FS and GS are transposedly connected together into one enlarged intermediate circuit. During this time, back contact I 39 is closed in parallel with back contact I34 and front contact I32 so that transformer secondary SI is shunted. This leaves but one transformer secondary in the circuit and reduces the impedance of the enlarged intermediate circuit in the case of rear end to head end conthrough the track circuit of relay EIZ to the section HS, then the intermediate circuit for section HS, which is only partially shown but which is similar to' that for section FS, will be transposedly connected with the circuit for section GS making one enlarged intermediate circuit. Dur-' ing this interval communication between the dis- Passing sidings are assumed to be provided at inalso desirable for the dispatcher to control the tervals that trains may pass each other. It is operation of the track switch for trains to leave and enter sidings. It is further desirable that the dispatcher control the operation of the power plant for furnishing electrical energy to the various relays, signals and switch mechanism motor. In such a lay-out, the arrangement of the communication circuits will be the same as that already explained for Fig.1. The commutator M6 controls the operation of the main line signals at each passing track end and the circuit for operating the switch mechanism for the motor M. The commutator 0M5 controls the operation of the power plant. Both commutators CMQ. and CMS are operated in the manner shown in Fig. 5. Let it be assumed that this method of switch and signal control is applied to the switches in Fig. I, and that the sections shown as double track in that figure are in reality sections of single track with a passing siding. Normally, trains keep to the main track unless there is necessity for them to enter the siding. Assume there are two trains, as No. and No. 6, approaching a passing track location. The dispatcher communicates with both as heretofore described in connection with Figure 1. The arrangement shown in Fig. 6 will be in use at each end of the siding so that switches F2 and F3. will both be controlled by the dispatcher. After communicating with the trains and instructing them that they are to pass at the station Y, train No. 6 to enter the passing siding and No. 5 to keep to the main line, and getting a reply from them that the instructions are understood, the dispatcher closes the switch W and operates the selective equipment DSE to send the appropriate code of impulses to the selector operating commutator 0M4, placing this commutator in the position 3. This opens the circuits at contacts Olli and 09 for control relays C6 and Cl causing both signals 6 and I to give the stop" indication. With the closure of contact Oll relay SR is energized and its contact III is caused to be made on its front point. This places the motor M in condition to operate to open the track switch F2 so that train No. 6 may enter the siding. The dispatcher again operates his selective equipment DSE sending out an appropriate code of impulses to operate the selector controlling commutator CMS operating this commutator to the position 2, which closes the ignition circuit for the gasoline engine GE through contact OI2 and the circuit for the starting motor ST through the contact Ol3.. The starting motor then operates from battery SY connecting itself through a suitable clutch with gasoline engine GE to turn the gasoline engine over to start same. As soon as gasoline engine GE has reached the speed at gizing switch motor M. Motor M now operates mechanism SM to open the switch and divert train No. 6 from the main line into the siding. As soon as the switch-is opened and locked in position, the contacts H5 and I56 in the circuit of control relay C8, and I90 and it! in the circuit of control relay C5, are closed so that both of the signals 8 and 5 will indicate proceed, unless the block of signal 5 is occupied at some other point holding said signal at stop. When train No. 6 arrives, findingsignal 8 clear it proceeds into the siding. Since track relays E5 and E6 control the relay H shown in Fig. 1, train No. 6 may announce its arrival on the siding to the dispatcher, similarly as heretofore described in the case of the trains operating as shown in Fig. 1. The dispatcher will now again operate the selector for commutator 0M4, returning this commutator to its normal position. This causes relays SR to become de-energized, that contact 2!! is made on its back point, thus causing the motor M to operate the mechanism SM to return the track switch F2 to its normal position. With track switch F2 returned to its normal position and the contacts 09 and Oil! back in their normal position, signals 1 and t are in a condition to indicate proceed except as their blocks may be occupied.

Train No. 5-in the meantime approaching on the main line, finding signal I. clear proceeds over the switch; but during the time that train No. 5 is on the main linebetween the siding switches F2 and F3, relay H- being de-energized, it reports its position to the dispatcher. As train No. 6 leaves the passing siding at the other end through switch F3, operated similarly as described for switch F2, it may announce its departure to the dispatcher as heretofore explained. Also, train No. 5 may announce its departure to the dispatcher when leaving the circuit of track relay E5, for example.

After the switch F2 has been returned to its normal position, the dispatcher again operates the selective system DSE to control the commutator CM5 to return same to its normal position, thus stopping the gasoline engine GE, and, consequently, operation of the power plant.

It is assumed that the charging of the battery SY by the generator U! will be at such a rate as to recuperate this battery for the drain upon it by the relays and signals during the interval when the power plant is not operating.

A principal feature of this invention is that of the communication zone for each train which in reality travels with the train and within the limits of which communications to and from the train are confined. Such a zone always includes a circuit, arbitrarily referred to as an intermediate circuit, in inductive relation with the train carried devices and adapted to be connected, when so desired. with communication devices in a wayside station. Such a station is more specifically referred to herein as the dispatcher's office. The operation of this traveling communication zone, or traveling intermediate circuit,

will nowbe described.

Assume a train in the section AS, which is but partly shown in Fig. 1. The communication zone for the train is confined to the intermediate circuit for section AS. When the train, moving toward the right, enters the track. circuit for relay.

E2, the separate identity oi the intermediate circuits of section AS and section BS is temporarily destroyed in that during the interval the train is in said track circuit, these two intermediate circuits are connected together m one circuit so that the limits of the communicating zone are now that of the two sections AS and BS.

When the train moves from the track circuit of relay E2, the intermediate circuit for each section AS and BS is restored to its normal status. The

' train now being wholly within the section BS its communicating zone and intermediate circuit is that for said section. As the train proceeds into the track circuit of relay E4, the communicating zone for the train is again changed by being enlarged to cover both sections BS and CS with the intermediate circuits for each section now combined into one correspondingly large intermediate circuit comprised within the said two sections. As the train moves from the track circuit for relay E4, the intermediate circuit for each of the sections BS and CS is restored to its side station may be placed in communicative relation with each other. This novel communication zone means admits of several trains being in the stretch at one time, each within its own communicating zone, and the attendants on each train end at liberty to communicate between themselves, or to be in communication with the wayside station, without interfering with, or being interfered with by, any other train which may be within the stretch but not in the same zone.

It will be noted that, as illustrated, when two adjacent intermediate circuits are joined together into one circuit, the conductors of the two sections are connected in transposed relation; for

example, with. a train in the circuit of track relay E4 of Fig.1, conductor 23 is connected to conductor l8 and conductor 20 is connected to conductor 25. The purpose of transpositions in these circuits, is to eliminate, or minimize, foreign current inductive disturbances. In certain localities, where foreign circuits, and other sources of inductive disturbances, are not present, transpositions in the intermediate circuits are not necessary. Further, where the. communication impulses are by certain frequenciesto which the various circuits, as necessar'y,are tuned, transfined myself solely to the use of transpositionspositions are not essential if the foreign current inductive effects are of frequencies differing from that used for communication purposes.

It will be further noted that I have not conin intermediate circuits when, and as, adjacent intermediatecircuits are joined for the interval a train is passing from one section to the section next adjoining. Figures 1 and 4 indicate transpositions of the conductors of the intermediate circuits at points between the limits of the sections. The number and style of transpositions desirable inan intermediate circuit are largely determined by conditions existing on the railroad where the installation is made. In this inVention I do not ,yvish to be limited to the transposing of the two conductors as shown in the figures. I may alternatively make such transpositions through transformers in a manner as illustrated in United States patent No. 1,899,105 granted February 28, 1933 to W. C. Phebus, on an application Serial No. 464,792 filed June 30, 1930.

There are certain advantages in the effects of v induction, where it exists, from foreign electrical disturbances in intermediate circuits of the communication system described. When the dispatcher connects his receiver circuit with an intermediate circuit, the audible efiect from the foreign current induced in the intermediate circuit serves as an indication that the intermediate circuit is complete and properly connected. Where such indication is desirable, this foreign current disturbance, may be used for this purpose, and thus the expense of special indication means is not necessary.

I have hereinbefore mentioned the use of radio frequencies as well as audio frequencies for conveying communications. I do not wish to be confined to the use of either or both of these. It

will be observed that the system is adaptable municative relation with each of said communieating sets connecting between said sets, and means for communicating between either or both endsof said train and a wayside station, comprising, said first named means, a communicating set in said wayside station, and a transformer normally in disconnected relation with said circuit but adapted to be selectively connected to said circuit and said wayside communicating set for establishing communicative relations between said train ends and said wayside station.

2. In a system for communication between a vehicle and a wayside station, communication sets on the vehicle and in the wayside station, an intermediate circuit in electrical relation with said vehicle carried set, a wayside circuit connecting to said wayside station-set, a transformer adapted for communication purposes, and means operative from the wayside station to connect said transformer in both said intermediate circuit and said wayside circuit.

' 3. In a system for communication between a vehicle in a stretch of track and a wayside'station, communication sets on the vehicle and in the wayside. station, a series of sections for said stretch each with a circuit normally in communicative relation with said vehicle carried set as the vehicle moves through the stretch, and a transformer adapted to be selectively placed in communicative relation with each of said circuits sets on the vehicle and in the wayside station, a communication zone .for the vehicle comprising a circuit within the zone to which communications to and from said vehicle are confined, and

from said wayside station and by said vehicle for connecting said two circuits to place said sets in communicative relation with each other.

7. In a system for communication between a plurality of vehicles and a wayside station, communication sets on each vehicle and in the waya side station, a communication zone for each vehicle, and means associated with each zone, at times controlled from said wayside station and at other times controlled jointly from said wayside station and by said vehicle, adapted to place any one vehicle, communication set or any several vehicle communication sets in communicative relation with said wayside station communication set.

8. In a system for communication between vehicles in a stretch of track and the wayside, sections of single track and double track in said stretch, a communication station on each of said vehicles, a communication station on the wayside, and means, adapted to place said wayside station in communicative relation with said vehicles, controlled by said vehicles as to each track or the double track sections and from the wayside station as to the single track sections.

9. In a system for communication between a vehicle in a stretch of track and a wayside station, communication sets on the vehicle and in the wayside station, a series of sections for said stretch each with an intermediate circuit in communicative relation with said vehicle carried set as the vehicle moves through the stretch, and

means associated with said intermediate circuits and'controlled from the wayside station through the medium of a single control circuit adapted to simultaneously place said wayside station set in communicative relation with a plurality of said intermediate circuits.

10. In a system for communication between ve hicles in a stretch of track and a wayside station, a wayside assemblage comprising, a series of sections in said stretch each with an intermediate circuit, a wayside communication station, and means common to adjacent intermediate circuits andassociated directly therewith operable to simultaneously place said wayside station incommunicative relation with said intermediate circuits in pairs.

11. In a system for communication between the head end and rear end of a train and between either or both ends of said train and a wayside station, a transmitting set on each end of the train including an inductor in circuit with a transmitter, a receiving set on each end of the train including another inductor in circuit with a receiver, a communication transmitting and receiving set in the wayside station} and means within a communicating zone, which travels with the train, communicatively connecting said inductors and adapted to be selectively placed in ,coil and a plurality of secondary coils, and 'a relay responsive to the operation of said selective means connecting one secondary coil into one intermediate circuit, another secondary coil into another intermediate circuit and said primary coil to said communication circuit.

13.. In a system for communication between a vehicle in a section of track and a wayside station, a wayside assemblage comprising, an intermediate circuit for said section, selective means operative from and a communication circuit connected with said wayside station, a transformer having a primary coil and a secondary coil, a relay responsive to the operation of said selective means having a normal position and an abnormal position, and means operative by the train while in said section effective, only when said relay is in the normal position. to connct said secondary coil into the intermediate circuit and said primary coil to said communication circuit. a

14. In a system for communication between a vehicle in a stretch of track and a wayside station, communication sets on the vehicle and in the wayside station, a series of intermediate circuits for said stretch each adapted to be in communicative relation with said vehicle carried set,

. each ofsaid circuits being adapted to be modifled to include means for communicative relationship with said wayside station set'in addition to its normal circuit elements, and means adapted to connect a plurality of said intermediate circuits together.

15. In a system for communication between the head end and the rear end of a train, a transmitting set on each end of the trainincluding an inductor in circuit with a transmitter, a receivlng set on each end of the train including another inductor in circuit with a receiver, andmeans operative in said receiver circuit adapted to render said receiver inactive while said transmitter is active.

16. In a train operating system under the comtrol of a dispatcher, a stretch of railway track including a section of single track line and a section of two track line, a train in said single track section-proceeding toward and into one of the tracks of said two track section, means permitting said train to 'pass from said single track section to said two track section, communication sets on said train and in the oiiice of said dispatcher, means for conveying communications betweenisaid dispatchers set and said-train set, selective means in said oflice adapted to control both said first named means and second named means, said second named" means being subject to such control only while the train is in the single track section, and means controlled by said train, controlling said second named means while the train is in the two track 'section.

17. In a system for communication between the head end and rear end of a train in a stretch of track and between either end or both ends of said train and a wayside station, communication to place said train sets in communicative relationwith each other, means in said station adapted to control said first named means to place said station set in communicative relation with either or both of said train sets for some portions of said stretch, and means controlled either by said train or by said means in said station for placing 19. In a train telephone system, in combination, two closed metallic loop circuits associated with a stretch of railroad track and'adapted to co-operate with telephone apparatus carried bytrains occupying the track, a telephone line, a transformer comprising a primary winding and two secondary windings, a switching device for simultaneously connecting the secondary windings in said two circuits, respectively, and for connecting the primary winding to said line, and a second switching device for joining said two circuits to form a single closed loop circuit and. for simultaneously short circuiting one of said secondary windings.

20. In a train telephone system, in combination, a stretch of railroad track, a train on said track, telephone apparatus carried by the train,

a normally closed electrical circuit consisting solely of a trackway conductor co-operating with the train carried telephone apparatus, a wayside conductor and switching contacts connectin said conductors together, a telephone line, a transformer having two windings, and a switch ing device for abnormally operating one of said,

contacts to connect one transformer winding in said circuit and for operating another contact to connect the other transformer winding to said line.

, 21. In a train communication system, in combination, a stretch of railroad track, a train on said track, transmitting and receiving apparatus on the train, a closed electrical circuit compris- 1 ing a trackway conductor co-operating with said transmitting and receiving apparatus, a wayside conductor and switching contacts connecting said conductors together, a transformer having two windings, a communication circuit, and a switching device controlled over said last circuit for operating one of said switching contacts to connect one transformer winding in said first circuit and for operating another switching contact to connect the other transformer winding to said last circuit.

22. A trackway system for conveying electrical impulses between a vehicle and a wayside station comprising a first circuit associated with a stretch oitrack for the vehicle, a second circuit extend ing from the stretch of track to the station, a transformer, a. relay controlled from said station normally connecting one winding of said trans former in said first circuit, and a vehicle controlled relay for connecting the other winding of said transformer in said second circuit.

23. In a train communication system, in combination, a stretch of railway comprising a double track line connecting at each end of the stretch to a single track line, a train in the stretch, a wayside station, an intermediate circuit associated with the double track line, a wayside line connecting to the wayside station, means controlled by the train on entering the stretch at either end thereof for connecting the intermediate circuit with the wayside line, and means associated with said intermediate circuit and controlled from said station for disconnecting said intermediate circuit from the wayside line.

24. In a communication system for railways, in combination, a stretch of track, a plurality of intermediate circuits electrically independent of each other, said circuits each being associated with a particular portion of said stretch of track, a transformer for each intermediate circuit, a wayside station, a communication circuit associated with the stretch of track and connecting with said station, andmeans controlled from the station over said co mmunication circuit for connecting one winding of each of any desired .number of said transformers in their associated intermediate circuits.

25. A trackway system for conveying signals to and from moving vehicles comprising, in combination, a series of electrically separate intermediate circuits associated with a stretch of track for vehicles, a transformer associated with adjoining circuits of said series for inductively connecting the circuits together under certain conditions, and means associated with said adjoining circuits for conductively connecting the circuits together under other conditions.

26'. In a communication system for railways, a stretch of railwayv track with a train therein, a wayside station, an intermediate circuit for said stretch, a wayside communication circuit connected with the wayside station, means associated with said intermediate circuit and controlled by s'aid train to connect the intermediate circuit with the communication circuit, and other means associated with said intermediate circuit controlled from said wayside station to annul said connection and thereafter to reconnect said trically connecting the intermediate circuit at said location with one of the adjoining intermediate circuits to form a single enlarged circuit, a relay controlled by the train, and contacts controlled by said relay for connecting the intermediate clrcuit for said location and also said enlarged circuit with said wayside communication circuit.

28. In a communication system for railways, a

stretch of railway including a main line track and 'a siding track, a switch at each end of the siding track connecting said track with the main line track, a wayside circuit associated with each of said tracks, a wayside station, a communication circuit extending from said station along 7 said tracks, means associated with the wayside circuit and controlled by a train moving over said tracks for automatically connecting the wayside circuit with the communication circuit, and

means associated with the wayside circuit and controlled over the communication circuit for interrupting the connection between said circuits, said connection between the circuits continuing after the same has been automatically established until said last means is operated.

29. In a system for conveying electric current between a vehicle and a wayside station, an electrical transmitting and receiving circuit on the vehicle and at the wayside station, a zone for the vehicle including at all times a circuitwithin the zone in electrical relation with the circuit on the vehicle and to which electric currents for and from said vehicle are confined, and means oper-- able by the vehicle in cooperation with means within said zone controlled from the wayside sta .tion for placing said station circuit and zone circuit in electrical relation with each other.

30. In a. system of communication for railway trains, a track district including a main line track and a siding track, said main line track extending away from said siding track in each direction, two trains, each on the main line track moving toward said siding, a communication set on each end of each of said trains, each set including a transmitter and a receiver and a train carried circuit adapted to be connected to said transmitter andreceiver, a circuit associated with said track for each of said trains in electrical relation with the train carried circuits, and a circuit associated with both said main line track and said siding track while one train is on the main line track and the other train is on the siding track in electrical relation with the train carried circuits of both trains, the arrangement being such that communication may be carried on between the ends of each of said trains as the trains approach the siding and between said trains while one train is on the main line track and the other train is on the siding track. 

